1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <linux/mm.h>
7#include <linux/sched.h>
8#include <linux/uaccess.h>
9#include <asm/ptrace-abi.h>
10#include <registers.h>
11#include <skas.h>
12
13extern int arch_switch_tls(struct task_struct *to);
14
15void arch_switch_to(struct task_struct *to)
16{
17 int err = arch_switch_tls(to);
18 if (!err)
19 return;
20
21 if (err != -EINVAL)
22 printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
23 "not EINVAL\n", -err);
24 else
25 printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
26}
27
28/* determines which flags the user has access to. */
29/* 1 = access 0 = no access */
30#define FLAG_MASK 0x00044dd5
31
32static const int reg_offsets[] = {
33 [EBX] = HOST_BX,
34 [ECX] = HOST_CX,
35 [EDX] = HOST_DX,
36 [ESI] = HOST_SI,
37 [EDI] = HOST_DI,
38 [EBP] = HOST_BP,
39 [EAX] = HOST_AX,
40 [DS] = HOST_DS,
41 [ES] = HOST_ES,
42 [FS] = HOST_FS,
43 [GS] = HOST_GS,
44 [EIP] = HOST_IP,
45 [CS] = HOST_CS,
46 [EFL] = HOST_EFLAGS,
47 [UESP] = HOST_SP,
48 [SS] = HOST_SS,
49 [ORIG_EAX] = HOST_ORIG_AX,
50};
51
52int putreg(struct task_struct *child, int regno, unsigned long value)
53{
54 regno >>= 2;
55 switch (regno) {
56 case EBX:
57 case ECX:
58 case EDX:
59 case ESI:
60 case EDI:
61 case EBP:
62 case EAX:
63 case EIP:
64 case UESP:
65 break;
66 case ORIG_EAX:
67 /* Update the syscall number. */
68 UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
69 break;
70 case FS:
71 if (value && (value & 3) != 3)
72 return -EIO;
73 break;
74 case GS:
75 if (value && (value & 3) != 3)
76 return -EIO;
77 break;
78 case DS:
79 case ES:
80 if (value && (value & 3) != 3)
81 return -EIO;
82 value &= 0xffff;
83 break;
84 case SS:
85 case CS:
86 if ((value & 3) != 3)
87 return -EIO;
88 value &= 0xffff;
89 break;
90 case EFL:
91 value &= FLAG_MASK;
92 child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
93 return 0;
94 default :
95 panic(fmt: "Bad register in putreg() : %d\n", regno);
96 }
97 child->thread.regs.regs.gp[reg_offsets[regno]] = value;
98 return 0;
99}
100
101int poke_user(struct task_struct *child, long addr, long data)
102{
103 if ((addr & 3) || addr < 0)
104 return -EIO;
105
106 if (addr < MAX_REG_OFFSET)
107 return putreg(child, regno: addr, value: data);
108 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
109 (addr <= offsetof(struct user, u_debugreg[7]))) {
110 addr -= offsetof(struct user, u_debugreg[0]);
111 addr = addr >> 2;
112 if ((addr == 4) || (addr == 5))
113 return -EIO;
114 child->thread.arch.debugregs[addr] = data;
115 return 0;
116 }
117 return -EIO;
118}
119
120unsigned long getreg(struct task_struct *child, int regno)
121{
122 unsigned long mask = ~0UL;
123
124 regno >>= 2;
125 switch (regno) {
126 case FS:
127 case GS:
128 case DS:
129 case ES:
130 case SS:
131 case CS:
132 mask = 0xffff;
133 break;
134 case EIP:
135 case UESP:
136 case EAX:
137 case EBX:
138 case ECX:
139 case EDX:
140 case ESI:
141 case EDI:
142 case EBP:
143 case EFL:
144 case ORIG_EAX:
145 break;
146 default:
147 panic(fmt: "Bad register in getreg() : %d\n", regno);
148 }
149 return mask & child->thread.regs.regs.gp[reg_offsets[regno]];
150}
151
152/* read the word at location addr in the USER area. */
153int peek_user(struct task_struct *child, long addr, long data)
154{
155 unsigned long tmp;
156
157 if ((addr & 3) || addr < 0)
158 return -EIO;
159
160 tmp = 0; /* Default return condition */
161 if (addr < MAX_REG_OFFSET) {
162 tmp = getreg(child, regno: addr);
163 }
164 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
165 (addr <= offsetof(struct user, u_debugreg[7]))) {
166 addr -= offsetof(struct user, u_debugreg[0]);
167 addr = addr >> 2;
168 tmp = child->thread.arch.debugregs[addr];
169 }
170 return put_user(tmp, (unsigned long __user *) data);
171}
172
173static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
174{
175 int err, n, cpu = task_cpu(p: child);
176 struct user_i387_struct fpregs;
177
178 err = save_i387_registers(userspace_pid[cpu],
179 (unsigned long *) &fpregs);
180 if (err)
181 return err;
182
183 n = copy_to_user(to: buf, from: &fpregs, n: sizeof(fpregs));
184 if(n > 0)
185 return -EFAULT;
186
187 return n;
188}
189
190static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
191{
192 int n, cpu = task_cpu(p: child);
193 struct user_i387_struct fpregs;
194
195 n = copy_from_user(to: &fpregs, from: buf, n: sizeof(fpregs));
196 if (n > 0)
197 return -EFAULT;
198
199 return restore_i387_registers(userspace_pid[cpu],
200 (unsigned long *) &fpregs);
201}
202
203static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
204{
205 int err, n, cpu = task_cpu(p: child);
206 struct user_fxsr_struct fpregs;
207
208 err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
209 if (err)
210 return err;
211
212 n = copy_to_user(to: buf, from: &fpregs, n: sizeof(fpregs));
213 if(n > 0)
214 return -EFAULT;
215
216 return n;
217}
218
219static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
220{
221 int n, cpu = task_cpu(p: child);
222 struct user_fxsr_struct fpregs;
223
224 n = copy_from_user(to: &fpregs, from: buf, n: sizeof(fpregs));
225 if (n > 0)
226 return -EFAULT;
227
228 return restore_fpx_registers(userspace_pid[cpu],
229 (unsigned long *) &fpregs);
230}
231
232long subarch_ptrace(struct task_struct *child, long request,
233 unsigned long addr, unsigned long data)
234{
235 int ret = -EIO;
236 void __user *datap = (void __user *) data;
237 switch (request) {
238 case PTRACE_GETFPREGS: /* Get the child FPU state. */
239 ret = get_fpregs(buf: datap, child);
240 break;
241 case PTRACE_SETFPREGS: /* Set the child FPU state. */
242 ret = set_fpregs(buf: datap, child);
243 break;
244 case PTRACE_GETFPXREGS: /* Get the child FPU state. */
245 ret = get_fpxregs(buf: datap, child);
246 break;
247 case PTRACE_SETFPXREGS: /* Set the child FPU state. */
248 ret = set_fpxregs(buf: datap, child);
249 break;
250 default:
251 ret = -EIO;
252 }
253 return ret;
254}
255

source code of linux/arch/x86/um/ptrace_32.c